It may have taken them over 20 years, but they've done it. Why? Could it be that they have decided they actually quite like each other? Improbable. It seems more likely that, neither being global or even national figures any more, it just no longer seems to matter. High-level feuding is for those with something to prove and something still to play for. And it generates lovely headlines and lots of public interest - so there's always a good reason to stick the knife in.
The latest to get nasty are Rupert Everett, taking a swipe at Boy George's weight, and Oasis, poking fun at Robbie Williams' avoirdupois. This kind of petty "you're fat" bitchiness is supposed to be the traditional preserve of women, but it seems men are quite able to dish it out as well - as they can the playground rivalry of primary school "best friends". Take Peter Mandelson and Gordon Brown, vying for Tony Blair's attentions. A new biography of the former Trade Secretary shows the two of them falling over each other to swop football cards and conkers with the most popular boy in the class, kicking each other on the shins to get closest. Blair had to write and plead with them to establish a better working relationship and to overcome what he called a "titanic but ultimately irrelevant feud". To no avail.
Meanwhile, Damon Albarn recently made a forlorn attempt to extend an olive branch to the ferocious Gallagher brothers, having been pretty comprehensively trounced in the "We're the most authentically streetwise and gritty band around, ner ner ner ner ner" competition they've been waging for the past four years. "It would be nice if we could all get along. I'm not being a hippy here but it would be nice if there was a harmonious thing musically in Britain," he offered plaintively. The Blur/Oasis vendetta turned out to be rather more taxing than he ever imagined. "I couldn't walk down the street without someone shouting 'Oasis!' People would open their windows and turn up Oasis. It was a nightmare."
But if the men are doing well, the women can still hold their own in the feuding stakes. Next month, the Julie Burchill Fan Club Convention is to be staged at the ICA. It will feature a shooting gallery with pictures of her enemies: so far Steven Berkoff, American feminist Camille Paglia, former colleague at the Modern Review Toby Young and the royal family will be in the firing range. "It sounds like the gallery is shaping up very well, but I'd like to add Annie Lennox," she told one interviewer, "because once when I was watching her on a Saturday morning children's TV show with my son Jack, who was about five, she upset him by saying she'd like to put my head in a food-mixer."
And last month, writers Victoria Glendinning and Shirley Conran fell out badly over their shared husband, Kevin O'Sullivan. Ms Conran described her former spouse as a "layabout" and dismissed their marriage as a "big mistake". Ms Glendinning, who is currently married to Mr O'Sullivan, was not best pleased. She fired off a letter warning: "If you do it again there will be hell to pay from me, so look out. This is the second time to my knowledge - there may have been more - that you have libelled him. Just how flaky can you get?" "She is obviously more interested in my ex- husband than I am and I wish her good luck with him. She'll need it," responded Ms Conran.
The question of how to resolve a public feud without both parties losing face is a tricky one. "If an argument comes from a public person, even if it is driven by pride and hatred, the stakes are much higher," says Susan Quilliam, a relationships psychologist and author of Stop Arguing: Start Talking (Vermilion, pounds 6.99). "Being seen to be wrong is a great loss of face." She says that some famous feuders don't want to make up. "Some may actually get off on the heightened publicity the argument gives them - it's something for the press to talk about." A public making-up is necessary, she says, plus a private agreement never to return to the bones of the quarrel in the future. But both parties must have some interest in making the reconciliation work. "One person can maintain a dignified silence, but it's very hard if the other is still making grand public statements," she says. However, she points out that favourable press coverage of a magnanimous make-up could be an advantage. "Look how Hillary gained brownie points by appearing as a mature individual over the situation with Bill."
But keep fighting and you'll hang on to the headlines, because a juicy on-going quarrel is irresistible - and always has been, since the days when Bette Davis's feud with Joan Crawford culminated in the remark: "The best time I ever had with Joan was when I pushed her down the stairs in Whatever Happened To Baby Jane."
VS BOY GEORGE
The two former friends have fallen out in a big way. "Who wants to see that big blob on telly?" asks Everett of George. "Too bad there's not a closet big enough for him to hide in." George ripostes: "I've seen Rupert's latest movie, and he certainly has a better body than me - but I've managed to keep my youthful looks and I don't have any lines."
VS GORDON BROWN
Constant bickering, storming and tantrums, according to the new Mandelson biography. Their mutual loathing dates back to 1994 when Mandelson refused to support Brown's bid to lead Labour after John Smith's death. Tony Blair attempted to peacemake in what he called a "titanic but ultimately irrelevant feud", but the task was beyond him.
VS REST OF SPICES
Front-woman Geri bailed out of the group and swapped the raunchy Spice image for her new role as a well-scrubbed UN ambassador. She hinted mysteriously at the depth of the schism. "There were adult reasons why I left, but our fans are children, and I didn't want to shatter their dreams." Conspicuously absent at Spice weddings and births since her abrupt departure.
VS ROBBIE WILLIAMS
The Gallaghers call Robbie "tubby-arsed Williams". Robbie Williams suggests that Oasis's musical ability is a bit limited: "I knew I could write poetry, but I also knew that I only knew three chords, and these three chords can't last forever ... unless you're Oasis." He is also sniffy about their rough manners. Speaking at a gig in Los Angeles, he said: "I'm nothing like my in-bred cousins from Manchester who spit on the audience."